In the audio/visual (AV) industry, a person may control an AV electronic device (e.g., a television) remotely using a “remote controller,” which is commonly called a “remote-control.” Typically, a remote controller works by sending control signals via an infrared (IR) light beam. This IR light beam is low enough in frequency that the human eye cannot see it, but the IR light beam can be detected by a receiver in a to-be-controlled AV device, such as a VCR.
Today, IR remote controllers are a standard feature on nearly all consumer electronics products, including TVs, VCRs, cable and satellite receivers, DVD players/recorders, AV equipment (e.g., radio and CD equipment), digital video recorders (DVRs), centralized media computers, etc. Typically, each AV electronic device has its own designated remote controller. Alternatively, some remote controllers are called “universal” because they are or can be programmed to control multiple different AV devices. Each AV device has a defined set of control codes, which are modulated onto an infrared light beam commonly using a 38 Khz carrier. For example, code “1343” may turn on Brand-X television, but have no effect on Brand-Y television. Conversely, code “6422” may change the channel on Brand-Y TV, but have no effect on Brand-X TV.
So as to avoid to inadvertently “controlling” electronic equipment through walls, IR technology for remote controllers was chosen to restrict the control to the equipment within the user's line of sight. Therefore, the typical remote controller technology ubiquitously employed by AV devices is designed to control a device within the same room as the user.
However, in some instances, consumers choose to distribute the AV outputs of their AV devices throughout their home (or business or other establishment) instead of buying duplicate equipment for each room. Equipment to distribute audio and video signals in a home is readily available today. Such distribution is most commonly done for AV output devices such as centralized media computers, satellite receivers, DVD players, DVRs and the like.
In these distributed AV layouts, some or many of the AV devices are located in a centralized AV closet or dispersed amongst several locations. Because of this, the user and the to-be-controlled AV devices are often located in different rooms. Consequently, the line-of-sight communications of IR remote controls is useless.
The following are some of the conventional approaches designed to address this line-of-sight restriction in a distributed AV layout: dedicated hardware, existing electrical wiring, and existing AV cabling.
Dedicated hardwire: This approach involves installing new wiring between the distributed and remote AV location (e.g., a bedroom) to a location of the to-be-controlled device (e.g., DVD in an AV media closet). The remote location will include a dedicated remote IR receiver connected to a connecting block and that block is connected to the dedicated wiring. That wiring is connected to an IR emitter in the media closest and that emitter is configured to emit IR to control the to-be-controlled device. This hardwire system requires that dedicated wires be run from room to room. This is particularly difficult and expensive to do with existing construction.
Existing Electrical Wiring: Instead of installing and using dedicated wiring, this approach uses existing wiring already found in a home or business. In this case, that wiring is the existing electrical wiring. While not designed to carry a communications signal, existing electrical wiring can be utilized to carry simple messages to devices plugged into that electrical wiring. However, this communication medium tends to be unreliable and prone to failure due to noise on the home's electrical system
Existing AV Wiring: Many homes have AV wiring. The most common form of this wiring is coaxial cable (simply called “coax”). Another conventional approach involves the insertion of the control code (from the IR remote controller) into the AV signal on the coax that is used to distribute AV throughout the home. However, this signal-insertion approach requires cumbersome signal injectors and puts noise on the video signal. This “noise” is often very noticeable to users as a video or sound “glitch” or “hiccup.”